Mothers who have breastfed previously and have adopted a child have been
successful in producing milk based on stimulation of their breast alone by the
infant suckling at their breast.
This is a slow process and some mothers may
never produce enough milk to totally feed their child.
This is termed relactation.

Women who have never been pregnant and whose breasts have not undergone
the hormonal preparation of pregnancy may produce a small amount of milk
based only on infant suckling at the breast.
However, these women usually produce
less milk than women whose breasts have been primed for breastfeeding by a
prior pregnancy.